Trello was the main tool that I used for a proof of concept for productising my consulting business. Clients, who are not in the tech industry, loved using it on their own time, and seeing when I was working on their files. It gave me the aha moment!
Simple and fast way to create a sketch of your future project. You have access to really good template that guide you in the creation of an project that will be desktop but also mobile. I use it to start all my projects.
I've built Electrician Path (www.electricianpath).com, Graveti (www.graveti.com) and now our familys roofing and exterior company with webflow (www.leveledgeco.com). I love how powerful webflow is and the capabilities.
I'm a big fan of Sharetribe and not only using their hosted platform to take ideas to live marketplaces, but also customizing it and then even running larger marketplaces (like Studiotime) using their Flex product. It's one of my go-to tools.
I love buy me a coffee because it is great for getting paid for any kind of work! I strongly believe that giving folks flexible options of how to support your work and even do so anonymously, is more appealing.